|Election||Premier at election||Premier's party||Premier after election||Premier's party|
|TAS 13 October 1956||Robert Cosgrove||Australian Labor Party||Robert Cosgrove||Australian Labor Party|
|TAS 19 February 1955||Robert Cosgrove||Australian Labor Party||Robert Cosgrove||Australian Labor Party|
|TAS 6 May 1950||Robert Cosgrove||Australian Labor Party||Robert Cosgrove||Australian Labor Party|
|TAS 21 August 1948||Robert Cosgrove||Australian Labor Party||Robert Cosgrove||Australian Labor Party|
|TAS 23 November 1946||Robert Cosgrove||Australian Labor Party||Robert Cosgrove||Australian Labor Party|
|TAS 13 December 1941||Robert Cosgrove||Australian Labor Party||Robert Cosgrove||Australian Labor Party|
Change of party leader: Beginning of Cosgrove's first period in office: Dwyer-Gray resigned in December 1939 as leader of the Labor Party and Premier in accordance with the undertaking he made to the Labor caucus on the death of Premier Ogilvie that he would act as interim party leader and Premier until the end of 1939. On Dwyer-Gray's resignation, Cosgrove, who had previous been elected as deputy leader, was confirmed as leader by caucus and was commissioned as Premier of an Australian Labor Party majority government; see Hughes and Graham, p. 262 (see 'Sources', below).
Parliamentary support: The Cosgrove government was returned at the general elections for the House of Assembly in December 1941 and November 1946, on both occasions with a majority of seats and, in the case of the December 1941 elections, with the support of over 62 percent of the primary vote.
Change of party leader: 'In December 1947 a Royal Commission led to criminal charges for bribery and conspiracy being laid against Cosgrove. On 15 December caucus elected Brooker leader pending a decision on the charges, and on 18th Cosgrove resigned and Brooker was commissioned [as Premier]', Hughes and Graham, p. 264, (see 'Sources', below); see also Townsley, pp 34-36 (see 'References', below).
References: For background on the period of postwar politics in Tasmania, see W A Townsley, Tasmania: Microcosm of the Federation or Vassal State, 1945-1983, pp 25-41, (Hobart: St David's Park Publishing, 1994), and note Terry Newman, Tasmanian Premiers 1856-1988: A Biographical Handbook, (Hobart: Tasmanian Parliamentary Library, ). For a survey of Labor Party politics in this period, see Richard Davis, Eighty Years' Labor: The ALP in Tasmania, 1903-1983, pp 37-57 (Hobart: Sassafras Books and the History Department, University of Tasmania, 1983, ISBN 0859012212).
For a survey of Cosgrove's career, see W A Townsley, 'Cosgrove, Sir Robert (1884 - 1969)', Australian Dictionary of Biography, Volume 13, pp 390-391, (Melbourne: Melbourne University Press, 1993), on line at: http://www.adb.online.anu.edu.au/biogs/A130561b.htm?hilite=Cosgrove
'Ministries: Names of the Members of Successive Ministries which have held Office in Tasmania since the inauguration of Responsible Government, together with the Dates of Appointment and Retirement', Journal of House of Assembly, Second Session of the Forty-Fifth Parliament of Tasmania, Anno LIII and LV Eliz II; Session 2 of the 45th Parliament, Volume 251, 2004-2006, (Hobart: Government Printer, Tasmania); Colin A Hughes and B D Graham, A Handbook of Australian Government and Politics 1890-1964, (Canberra: Australian National University Press, 1968, SBN 708102700), and the website of the Parliament of Tasmania, http://www.parliament.tas.gov.au/